Java 8

Question

我在找到时间差异时遇到了一些问题，如果我试图在今天的时间找到差异（比如说t1 =＆＃34; 08：00：00＆＃34;以及t2 =＆＃34; 10:00:00 && ＃34;然后它给出了正确的输出，但是当我试图找到差异时，如t1 =＆＃34; 20：00：00＆＃34;（今天的时间）和t2 =＆＃34; 08:00 ：00＆＃34;（第二天早上），我希望输出为12小时，但输出错误。请帮助我。

    String t1 = "20:00:00"; 
    String t2 = "12:00:00";
    String t3 = "24:00:00";
    SimpleDateFormat sDf = new SimpleDateFormat("HH:mm:ss");
    Date d1 = sDf.parse(t1);
    Date d2 = sDf.parse(t2);
    Date d3 = sDf.parse(t3);
    long s1,s2,s3,s4,dif1,dif2,dif3,minutes,hrs;
    dif1 = d2.getTime() - d1.getTime();
    s1 = dif1/1000;
    System.out.println("s1 "+s1);
    if(s1<0){
        dif2 = d3.getTime() - d1.getTime();
        s2 = dif2/1000;
        System.out.println("s2 "+s2);
        dif3 = d2.getTime();
        s3 = dif3/1000;
        System.out.println("s3 "+s3);
        s4 = s2+s3;
        minutes = s4 / 60;
        s4 = s4 % 60;
        hrs = minutes / 60;
        minutes = minutes % 60;
        System.out.println("time difference is : "+hrs+": "+minutes+" :"+s4);
    }else{
        minutes = s1 / 60;
        s1 = s1 % 60;
        hrs = minutes / 60;
        minutes = minutes % 60;
        System.out.println("time difference is : "+hrs+": "+minutes+" :"+s1);
    }

Answer 1

任何日期/时间操作/计算都应该通过使用定义良好且经过测试的API来完成，例如Java 8的Time API或Joda Time

Java 8

public class TestTime {

    public static void main(String[] args) {
        // Because of the ability for the time to roll over to the next
        // day, we need the date component to make sense of it, for example
        // 24:00 is actually 00:00 of the next day ... joy
        LocalDateTime t1 = LocalTime.of(20, 00).atDate(LocalDate.now());
        LocalDateTime t2 = LocalTime.of(12, 00).atDate(LocalDate.now());
        LocalDateTime t3 = LocalTime.MIDNIGHT.atDate(LocalDate.now()).plusDays(1);

        if (t1.isAfter(t2)) {
            System.out.println("Before");
            Duration duration = Duration.between(t2, t3);
            System.out.println(format(duration));
        } else {
            System.out.println("After");
            Duration duration = Duration.between(t2, t1);
            System.out.println(format(duration));
        }
    }

    public static String format(Duration duration) {
        long hours = duration.toHours();
        duration = duration.minusHours(hours);

        return String.format("%02d hours %02d minutes", hours, duration.toMinutes());
    }

}

哪个输出

12 hours 00 minutes

我在代码中似乎无法回答的问题是您执行此操作的原因s4 = s2+s3;，基本上将12:00添加到24:00

Answer 2

查看一些选项here

如：

     LocalDate today = LocalDate.now()
     LocalDate yeasterday = today.minusDays(1);
     Duration oneDay = Duration.between(today, yesterday);
     Duration.between(today.atTime(0, 0), yesterday.atTime(0, 0)).toDays()   // another option

Answer 3

String time1 = "08:00:00";
String time2 = "17:00:00";

SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");
Date date1 = format.parse(time1);
Date date2 = format.parse(time2);
long difference = date2.getTime() - date1.getTime();

Answer 4

不使用Java 8或Joda-Time，并确保不涉及本地时区DST。

public static void printDiff(String time1, String time2) throws ParseException {
    SimpleDateFormat df = new SimpleDateFormat("HH:mm:ss");
    df.setTimeZone(TimeZone.getTimeZone("UTC"));
    int seconds = (int)(df.parse(time2).getTime() - df.parse(time1).getTime()) / 1000;
    if (seconds < 0)
        seconds += 24 * 60 * 60;
    int minutes = seconds / 60;
    int hours = minutes / 60;
    seconds %= 60;
    minutes %= 60;
    System.out.printf("There are %d hours %d minutes %d seconds from %s to %s%n",
                      hours, minutes, seconds, time1, time2);
}

测试

public static void main(String[] args) throws Exception {
    printDiff("08:00:00", "10:00:00");
    printDiff("20:00:00", "08:00:00");
    printDiff("15:47:22", "11:12:38");
    printDiff("08:00:00", "07:59:59");
    printDiff("08:00:00", "08:00:00");
}

输出

There are 2 hours 0 minutes 0 seconds from 08:00:00 to 10:00:00
There are 12 hours 0 minutes 0 seconds from 20:00:00 to 08:00:00
There are 19 hours 25 minutes 16 seconds from 15:47:22 to 11:12:38
There are 23 hours 59 minutes 59 seconds from 08:00:00 to 07:59:59
There are 0 hours 0 minutes 0 seconds from 08:00:00 to 08:00:00

Java发现时间差异

4 个答案:

Java 8